The heightened demand for the flu vaccine has caused some providers to run out of doses, however officials said there are still plenty to go around and are encouraging people to call ahead before driving to a local clinic to get immunized.

National drug store chain Rite Aid is moving some of its supplies around to make sure each of their locations remain stocked, spokeswoman Ashley Flower said.

"In select areas, just like everybody else, we are experiencing a reduced amount of shots," Flower told ABC News Radio. "We would certainly advise our customers to call their local Rite Aid before coming in to see what the status of the vaccine is at their location."

A new supply of the flu vaccine is expected to arrive in stores early next week, Flower said.

One helpful tool for people looking to be immunized is the HealthMap Vaccine Finder, which includes 40,000 locations across the United States and allows users to enter their ZIP codes to find a nearby provider of the flu vaccine.

Demand for the vaccine has surged as the flu crossed into epidemic territory. The Centers for Disease Control and Prevention said cases have been recorded in 47 states, however there are early signs flu cases may have peaked in some parts of the country, officials said.

Five fewer states reported high flu activity levels in the first week of January than the 29 that reported high activity levels in the last week of December, according to the CDC's weekly flu report. This week, 24 states reported high illness levels, 16 reported moderate levels, five reported low levels and one reported minimal levels, suggesting that the flu season peaked in the last week of December.

Despite the glimmer of good news, CDC officials said the virus could still make a comeback in the final weeks of the season and urged Americans to make sure they get flu shots.

"It's not surprising. Influenza ebbs and flows during the flu season," Dr. Thomas Frieden, director of the CDC, said in a Friday morning teleconference. "The only thing predictable about the flu is that it is unpredictable."

State officials are taking steps in order to protect the public's health.

New York Gov. Andrew Cuomo declared a public health emergency today, allowing pharmacists to administer vaccines to patients six months to 18 years old. The executive order suspended a state law that limited immunizarions to people over 18 years of age.

ABC News chief health and medical editor Dr. Richard Besser said this could be "the worst flu in a decade".

"We don't know when this is going to end," he said.

When deciding whether to stay home from work or seek medical attention, Besser said there is a key difference between the common cold and influenza.

"If you think about a cold, it usually affects you from the neck up -- congestion, sinus fullness, sore throat," Besser said. "But the flu is going to affect your whole body. You're going to feel achy all over."